Drain valve



FIG. 1 is a top perspective view of a drain valve.

FIG. 2 is a top rear perspective view of the drain valve.

FIG. 3 is a top plan view of the drain valve.

FIG. 4 is a right side elevational view of the drain valve.

FIG. 5 is a left side elevational view of the drain valve.

FIG. 6 is a bottom plan view of the drain valve.

FIG. 7 is front elevational view of the drain valve; and,

FIG. 8 is a rear elevational view of the drain valve.

The broken lines shown in the figure are included for the purpose of illustrating portions of the drain valve and form no part of the claimed design. 

CLAIM The ornamental design for a drain valve, as shown and described. 